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daube-1I- ,Estabas Letters Patent No. 97,163, dated November 23, 1869.

IMPRovEn RAILWAY-FROG.

The Schedule referred to in these Letters Patent and making part of thesame To all to whom these presents shall-come:

Be it known that I, Fnnnnmcx J. CALHOUN, of Boston, in the county ofSuffolk, and Commonwealth ot Massachusetts, have made an invention of anew and useful Improvement in Railway-Frogs; and do hereby declare thebllowing to be a all, clear, and exact description thereof, duereference being had to the accompanying drawings, making part of thisspecifica tion, and in which- Figure lis a perspective representation,and

Figure A2, a vertical and transverse section ofa frog containing myimln'oif'ement.

This invention consists in the interposition, between the 4metallicplates composingr the body of a railwayfrog, of'hardened pulp frompaper-stock or other fibrous substances or tissues.

I am aware vthat previous to the origin of the improvements hereindescribed, one or more strata of wood have been employed between themetallic plates of railway-frogs. A

I have found, by careful experiments, that a hardened or dried pulp,composed after the manner, or of the materia-ls used inramper-manutacture, or of ations other fibrous substances orpreparations, is

-much better calculated, than wood, to resist the impact, concussion, orthrusts, to which a railway-frog is constantly subjected, and that itpossesses, in addition to its capability otretaining` for a great lengthottime its primitive shape, an immunity from deca- )v not found in wood.t

It also embodies a certain degree of elasticity in excess of thatpossessed by wood, and I am coniident that this elasticity is ofsutcient extent to render the employment of an additional elasticmaterial, such as' India rubber or gntta-percha, unnecessary, althoughthis materialmayhof course, be combined with it, if y desirable.'

In the drawings attached to this specification, and in ,which myimprovement is exhibited- A denotes an oblong and tlat metallic plate,to the. upper ace of which are secured the heel-plate B, and side railsor guides I) l), aseeond metallic plate E heilig disposed below thefirst-mentioned or rail- I plate A, while an additional and third plateF is iu turn disposed below the second plate E, a strip or layer ofwood, G or H, heilig interposed between the plates A, E, and F, and-thewhole bolted securely together,-the point c passing through andsustained by the upper plate A, and resting upon the second plate.

This construction ot the ti'oo without the wood os-` sesses nopatcntable novelty, and is in extensive use.

In carrying out my imprm'en'ient, comprising the subject-matter of thispatent, I dispense with the wooden filling hereinbct'ore described, andsubstitute in lieu thereof', sheets or plates of hardened pulp, composedof' a librous material, and produced by anyof the well-known processesadopted in paper-maxim facture, or otherwise obtained, to eicct thedesired result.

This pulp is to be rendered impervious to moisture by incorporation orimpregnation with shell-ac or other analogous subst-ance, properlyprepared to effect an intimate union.

I am aware that felt has been used for a like purpose in railway-frogs,and this I do not claim; but

What I claim as my invention, and desire to secure by Letters Patent, isl The employment, in a railway-frog, ot one or more harchued andn'ater-yroot sheets ot` pulp, made from paper or other fibrous material,substantially as and for the purposes herein set forth. Y

Vitnesses: FREDERICK J. CALHOUN.

FRED. CUR-Tis, EDWARD GRIFFITH.

